In recent years it has become increasingly popular to provide promotional material of the game type in which players are obliged to purchase quantities of a particular manufacturer's goods in order to continue to play the game. Numerous expedients have been developed for such purpose. One of the more popular in the art of manufacture of cans for the containment of beverages and the like relates to cans of the type in which a ring is attached to a detachable portion of an end of the can. A consumer of the beverage within the can pulls on the ring with a finger and removes a section of the end. Promotional materials such as a portion of a puzzle or one element of a "bingo" type game or the like is concealed by being printed on the under side of the removable portion of the can end and is exposed only by removal thereof. Accordingly, the consumer must open the can in order to play the game.
This can end structure has the very significant defect that once the consumer opens the can he is left with a pull tab and ring attached thereto which are detached from the can. Human nature being what it is many of these tabs are not properly disposed of but become litter. This has resulted in this type of can end structure being made illegal in many states.
The ring top/detachable portion can end structure has been supplanted in many cases by the so-called "retained tab" end structure in which a tab permanently riveted to the can end pivots upon a consumer's desiring to open the can and a portion of the tab comes into contact with a portion of the end of the can outlined by a partly circular score line defining an opening. When the consumer pulls one end of the tab further away from the can end, it pivots about a hinging line, and its other end pushes harder on the score-defined portion of the can used. Eventually the portion of the can end outlined by the score line pivots about the unscored portion of the circular line and is pushed inwardly into the can, thus opening it and permitting the consumer to have access to the contents of the can. In this way the can can be opened without use of tools, while neither tab nor the opening portion of the end become detached from the can itself.
However, it will be appreciated that it is not satisfactory to place concealed promotional information on the underside of the portion of the can end which is rotated into the can upon opening as this is invisible to the user. Moreover, it is not convenient to print advertising or other promotional material on the under side of the tab due to the nature of the sequence of manufacturing operations commonly used to manufacture such tabs. Nor would it be possible to scribe or indent promotional material into the tab, as even if it were scribed onto the underside of the tab it would tend to print through to the upper side thus allowing the consumer to see what the promotional material was prior to opening the can, which would be undesirable particularly in the case of contests having monetary or other valuable prizes.
Accordingly, there is a need in the art for a can end of the type which can be opened without tools and without detachment of any portion of the can end from the can proper, while permitting provision of concealed promotional material thereon.